278
ATmega16M1/32M1/64M1 [DATASHEET]
8209E–AVR–11/2012
27.4
Signature bytes
All Atmel microcontrollers have a three-byte signature code which identifies the device. This code can be read in
both serial and parallel mode, also when the device is locked. The three bytes reside in a separate address space.
For the Atmel ATmega16M1/32M1/64M1 the signature bytes are given in
Table 27-8.27.5
Calibration byte
The ATmega16M1/32M1/64M1 has a byte calibration value for the internal RC Oscillator. This byte resides in the
high byte of address 0x000 in the signature address space. During reset, this byte is automatically written into the
OSCCAL Register to ensure correct frequency of the calibrated RC Oscillator.
27.6
Page size
27.7
Parallel programming parameters, pin mapping, and commands
This section describes how to parallel program and verify Flash Program memory, EEPROM Data memory, Mem-
ory Lock bits, and Fuse bits in the ATmega16M1/32M1/64M1. Pulses are assumed to be at least 250ns unless
otherwise noted.
27.7.1
Signal names
In this section, some pins of the Atmel ATmega16M1/32M1/64M1 are referenced by signal names describing their
functionality during parallel programming, see
Figure 27-1 and
Table 27-11. Pins not described in the following
table are referenced by pin names.
Table 27-8.
Signature bytes.
Part
Signature bytes address
0x000
0x001
0x002
ATmega16M1
0x1E
0x94
0x84
ATmega32M1
0x1E
0x95
0x84
ATmega64M1
0x1E
0x95
0x84
Table 27-9.
No. of words in a page and no. of pages in the flash.
Device
Flash size
Page size
PCWORD
No. of pages
PCPAGE
PCMSB
ATmega16M1
8K words
(16K bytes)
64 words
(128 bytes)
PC[5:0]
128
PC[12:6]
12
ATmega32M1
16K words
(32K bytes)
64 words
(128 bytes)
PC[5:0]
256
PC[13:6]
13
ATmega64M1
32K words
(64K bytes)
128 words
(256 bytes)
PC[6:0]
256
PC[14:7]
14
Table 27-10. No. of words in a page and no. of pages in the EEPROM.
Device
EEPROM size
Page size
PCWORD
No. of pages
PCPAGE
EEAMSB
ATmega16M1
512 bytes
4 bytes
EEA[1:0]
128
EEA[8:2]
9
ATmega32M1
1024 bytes
4 bytes
EEA[1:0]
256
EEA[9:2]
9
ATmega64M1
2048 bytes
8 bytes
EEA[2:0]
256
EEA[9:2]
9